Containment areas surrounding chemical process equipment such as tanks, pipes, and valves are often constructed of concrete. This concrete has to be protected from exposure to aggressive chemical environments. Four major factors affect lining or coating product selection: chemical exposure, compatibility with the substrate, application conditions, and type of exposure. Also, the nature of concrete, the frequent requirement for traffic-bearing surfaces, and the aggressiveness of the chemical environment make thick film coatings and linings the best choice.
Conventional epoxies have excellent resistance to alkalies and can be formulated to exhibit minimal shrinkage. Polyesters and vinyl esters excel in resisting oxidizing acids and are exceptionally good in bleaches. They must be applied on dry concrete, though, because their cure is sensitive to moisture. Phenolics are resistant to most strong acids and many solvents, but they have poor resistance to most strong alkali materials. Furans possess excellent chemical resistance, but shrinkage cracking upon cure must be controlled for furans to be used successfully as a lining material.